<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <script>
     
    while (true) {
      let str = prompt('do you love me?')
      if (str === 'yes'){
        alert('yes me too')
      break
      }
      
    }
  </script>
</body>
</html>